\begin{tikzpicture}[
    bend angle=45,
    place/.style={shape=circle, fill=blue!20, 
        draw=blue!80, minimum size=1cm},
    transition/.style={shape=rectangle, fill=black!20, 
    draw=black!80, minimum size=8mm},
    pre/.style={->, shorten <= 1pt, semithick},
    post/.style={<-, shorten >= 1pt, semithick},
    red place/.style={circle, minimum size=1cm, fill=red!20, draw=red!75}
]
    \node [place, tokens=1](w1){};
    \node [place, below=of w1](c1)  {};
    \node [place,below=of c1, label={[red, above]$s \le 3 $}](s1) {};
    \node [transition, left=of c1](e1) {}
        edge[post,bend left] (w1)
        edge[pre] (c1)
        edge[pre, bend right](s1);
    \node [transition,right=of c1, ](l1) {}
        edge[post] (c1)
        edge[post, bend left] (s1)
        edge[pre, bend right] node[auto, swap]{2} (w1)
    ;

    \node[place, below=of s1](c2){};
    \node[place, below=of c2, tokens=1](w2){};
    \node[transition, left=of c2](e2){}
        edge[post, bend left] (s1)
        edge[pre, bend right] (w2)
        edge[pre](c2);
    \node[transition, right=of c2](l2){}
        edge[pre, bend right](s1)
        edge[post](c2)
        edge[post, bend left](w2);
    
    
    \begin{scope}[on background layer]
        \node(r1)[fill=black!30, fit=(w1)(e1)(c1)(s1)(l1)(e2)(c2)(l2)(w2)]{};
    \end{scope}

    \begin{scope}[xshift=8cm]
        \node[place](w1'){};
        \node[place, below=of w1'](c1'){};
        \node[transition, left=of c1'](e1'){}
            edge[post, bend left](w1')
            edge[pre](c1');
        \node[transition, right=of c1'](l1'){}
            edge[post](c1')
            edge[pre, bend right](w1');
        \node[red place, below=of e1', xshift=8mm, label={[red]left:s1}](s1'){}
            edge[post](e1')
            edge[pre](l1');
        \node[red place, below=of l1', tokens=3, xshift=-8mm, label={[red]right:$\bar s$}](s2'){}
            edge[post](l1')
            edge[pre](e1');
        \node[transition, below=of s1', xshift=-8mm](e2'){}
            edge[pre](s1')
            edge[post](s2')
            ;
        \node[place, right=of e2'](c2'){}
          edge[post](e2');
        \node[transition, right=of c2'](l2'){}
          edge[post](c2')
          edge[pre](s2')
          edge[post](s1');
        \node[place, below=of c2'](w2'){}
          edge[post, bend right](l2')
          edge[pre, bend left](e2');
    \end{scope}

    \begin{scope}[on background layer]
        \node(r2)[fill=black!20, fit=(w1')(e1')(c1')(l1')(s1')(s2')(e2')(c2')(l2')(w2')]{};
    \end{scope}

    \begin{scope}
        \draw[->, decorate, red, decoration={snake, pre length=2mm,  post length=2mm}](r1) -- 
          node[text width=3cm, above=1mm, align=center, midway]
          {replacement of the \textcolor{red}{capacity} by \textcolor{red}{two places}} (r2);
    \end{scope}

    %\draw[->](w1) edge[bend right] (e1);
    %\draw[->](e1) edge (c1);
    %\draw[->](e1) edge[bend right](s1);
    %\draw[->](c1) edge (l1);
    %\draw[->](s1) edge [bend right] (l1);
    %\draw[->](l1) edge[bend right] node[auto,swap]{2} (w1); 


\end{tikzpicture}